There is only one MAPI public folder hierarchy that a single Exchange organization can support

Turning of ADUC Advance futures will give you chance to see some additional objects within AD, as well as see the

• Lost and Found (Default container for orphaned objects)
  


• Microsoft Exchange system object (The public folder directory object lives under the Microsoft Exchange System Objects)
  


• NTDS Quotas (This container is responsible for storing objects which are used to assign ownership quotas for users, groups, computers, or services)
  


• Program data (This is used by directory related applications to store information within the Active Directory database)
  


• System (The largest and most useful of the hidden containers, this is used to store a variety of system services and objects)
  


• 
  

Another important part of the client public folder experience is the actual Public Folders tree that you can expand to see the public folder hierarchy. The Public Folders object is an Active Directory object that lives under the Administrative Group's Folders object. There is only one MAPI public folder hierarchy that a single Exchange organization can support.

This tree object is located in the administrative group that had Exchange 200x installed into it first. The Public Folders object has an attribute that points to every public folder store that is associated with it. You can move this specific object between administrative groups by just dragging and dropping it in Exchange System Manager

http://www.microsoft.com/technet/prodtechnol/exchange/2003/pubfoldersbp.mspx

Additional Advanced Settings

When you configure the Advanced Features, you now see additional containers within the ADUC. These containers include the following containers, which provide the described functions:

LostandFound - This container is used to house Active Directory objects that are orphaned with the directory. This might occur by an administrator deleting a container or OU, while another administrator is attempting to move an object to that same container or OU. This is a way to protect and store objects that don't have an existing container within the Active Directory anymore.

NTDS Quotas - This container is responsible for storing objects which are used to assign ownership quotas for users, groups, computers, or services. The ownership quotas limit the number of Active Directory objects that can be owned by any other object within Active Directory. This is not used very often, which is one reason it is hidden by this feature.

Program Data - This is used by directory related applications to store information within the Active Directory database.

System - The largest and most useful of the hidden containers, this is used to store a variety of system services and objects. This includes the Group Policy Containers, DFS configurations, IPSec settings, WinSock configurations, and WMI Policies, just to name a few.

By the way, after you enable the Advanced Features within the Active Directory, you will also be able to see the Security tab when looking at the properties of any of the Active Directory objects.

Microsoft Exchange system object - (The public folder directory object lives under the Microsoft Exchange System Objects)

Having only one MAPI public folder, usable to one Exchange org is good to remember. It also helps to clears the confusion about Public Folders within Exchange environment, and makes a little easy to understand how Exchange is relaying on Active directory and of course DNS.

Best Regards

Oz Ozugurlu